ABS have more shrinkage than PLA. If you have thick corner on your model, the material have internal force to warp. There are some technic to solve this problem: 

1) Changing to PLA is the easiest way to solve this problem. 

2) Add a thin extension pad around the corner can increase stickiness to the platform. 

3) Reduce thickness of corner, ex: add hole on thick wall. 

4) Reduce distance between nozzle and platform, heat platform to 85C degree. To increase stickiness. 

Reference for advance user: [[can_i_increase_heat_bed_output_watt|Increase heat bed output power]]